Ashrae Journal - October 2008 - (Page 42) – Cabinet Loss: 0.35 in. w.c. (87 Pa) – Supply Duct Loss: 1 in. w.c. (249 Pa) • Motor Power: 20.8 kW (0.92 motor efficiency × 1.05 drive loss) • Net Sensible Cooling: 56.8 tons (200 kW) • Leaving Air Temperature: 56.3°F (14°C) (from Equation 3) • Chilled Water Pump Power: 2.8 kW (from Equation 2) The above four CAHUs combined would add an additional 83.2 kW fan power plus 11.2 kW chilled water pump power above and beyond the 750 kW IT and lighting load. This scenario yields a total chiller load of 888 kW at a sensible heat ratio of 0.95. Conclusion Although row-based cooling has a sizable advantage in operational cost savings, it will not be a silver bullet for all applications. Certainly, there are far more existing data centers than new ones being built, and it is likely that a mix of cooling architectures, including all of the above mentioned, will be deployed within the same data center. As data centers evolve and densities increase, a hybrid approach to cooling various density heat loads is the likely result. However, new data center space (whether expansion or entirely new) should always consider row-based cooling for the best energy efficiency and predictability whenever possible. Acknowledgments The annual electrical cost of three cooling architectures: IRAH, CRAH, and CAHU are given respectively $139,572, $201,878, and $197,211 (at $0.10/kWh). Of course, the magnitude of savings would vary due to chiller plant efficiency, utility cost, and base IT and lighting loads. The row-based cooling architecture versus the other two choices affords a two-thirds reduction in fan power consumed by cooling equipment, with additional savings compounded throughout the 9/23/08 7:44 entire downD50318asjl_703523a:D50318asjl_703523a stream cooling infrastructure. Special thanks to Mr. Andrew Kelly, commercial sales and service manager of Carrier Corporation, for his timely assistance with chiller performance data. References 1. 1992 ASHRAE Handbook—HVAC System & Equipment, Cooling Towers. 2. American Power Conversion. “InRow RC Technical Data Manual 990-2846A-001.” AM Air Movement and Control Association International. 2007. 3. Page 1 AMCA Publication 201-02 (R2007), Fans and Systems. CRITICAL CLEANING DEMANDS GOODWAY. FLOWHOOD ELECTRONIC FLOWHOOD DIRECT DIGITAL READOUT 25-2500 CFM CHILLER TUBE CLEANERS FOR SMOOTH AND ENHANCED TUBES Goodway’s line of Ream-A-Matics® makes tough tube cleaning a simple, one-person operation. Each machines uses a variety of quick connect brushes and cleaning tools mounted to the tip of a rotating flexible shaft, along with a simultaneous water flush, to remove deposits. Both electric and air powered units are available, as well as units with reversible shaft rotation, a shaft feeder gun, chemical injection, and a 500 PSI power flush. So the next time you need to clean your chiller — clean it the good way. To find out more, call Goodway today at 800-333-7467, or visit us online at www.goodway.com. AUTOMATICALLY CORRECTS FOR AIR DENSITY & BACKPRESSURE CHOICE OF METERS - AIR FLOW ONLY, OR AIR FLOW, VELOCITY, PRESSURE & TEMPERATURE OPTIONS INCLUDE: MEMORY, AVERAGE & SUM TO 2000 READINGS, SEQUENTIAL RECALL, AUTO-READ REPAIR POLICY - TWO WEEK TURNAROUND OR LESS CUSTOM TOPS MADE TO ORDER ® Shortridge Instruments, Inc. 7855 East Redfield Road • Scottsdale, Arizona 85260 (480) 991-6744 FAX (480) 443-1267 www.goodway.com 42 Innovative Maintenance Solutions www.info.hotims.com/16018-32 www.info.hotims.com/16018-54 ASHRAE Journal October 2008 http://www.goodway.com http://www.goodway.com http://www.goodway.com http://www.info.hotims.com/16018-32 http://www.info.hotims.com/16018-54
Table of Contents Feed for the Digital Edition of Ashrae Journal - October 2008 Ashrae Journal - October 2008
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.